Docs: Update dashboard.md (#21896)

Fix typo in templating JSON

docs/sources/reference/dashboard.md

@@ -183,7 +183,6 @@ The `templating` field contains an array of template variables with their saved
         ],
         ],
         "query": "tag_values(cpu.utilization.average,env)",
         "query": "tag_values(cpu.utilization.average,env)",
         "refresh": false,
         "refresh": false,
-        "refresh": false,
         "type": "query"
         "type": "query"
       },
       },
       {
       {